Table 3.

The top ten medication alerts occurring at least 20 times that were generated by system 2 and had the lowest positive predictive values

Alert text	Nrelevant†	Ntotal‡	PPV* (%)
Drug duplication: different strength, same mechanism of action	0	74	0.0
Selective β-blockers+insulin	0	43	0.0
β-Blockers+oral hypoglycemic drugs	0	25	0.0
α-Blocking drugs (for benign prostate hyperplasia)+β-blockers/calcium channel blockers	0	23	0.0
Renal function: bumetanide	0	20	0.0
Renin-angiotensin-aldosterone system (RAAS) inhibitors+diuretics	2	120	1.7
Salicylates antithrombotic+NSAIDs (other than ibuprofen)	1	51	2.0
RAAS inhibitors+potassium(-saving diuretics)	1	41	2.4
NSAIDs+corticosteroids	2	61	3.3
Bisphosphonates+antacids/iron/calcium	2	44	4.5

^*PPV (positive predictive value)= $\frac{\text{number of relevant medication alerts}}{\left(\text{number of relevant medication alerts + number of irrelevant medication alerts}\right)}$.

^†N_relevant indicates the number of clinically relevant medication alerts.

^‡N_total indicates the total number of medication alerts.

NSAID, non-steroidal anti-inflammatory drug.